diff --git a/.github/workflows/contract-validation.yml b/.github/workflows/contract-validation.yml
new file mode 100644
index 0000000..4f3f061
--- /dev/null
+++ b/.github/workflows/contract-validation.yml
@@ -0,0 +1,19 @@
+name: Provider Contract Validation
+
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+
+jobs:
+  validate-tinynode-to-rerum:
+    uses: cubap/rerum_openapi/.github/workflows/seam-runtime-validation.yml@main
+    with:
+      contract_repo_ref: main
+      seam_manifest_path: seams/tinynode-to-rerum/manifest.yaml
+      target_base_url: https://store.rerum.io/v1
+      compare_paths: true
+      compare_operations: true
+      fixture_file: test/contract-fixtures/tinynode-to-rerum.yaml
+      timeout_ms: 10000
diff --git a/.github/workflows/sync-core-provider-contract.yml b/.github/workflows/sync-core-provider-contract.yml
new file mode 100644
index 0000000..6848ef8
--- /dev/null
+++ b/.github/workflows/sync-core-provider-contract.yml
@@ -0,0 +1,48 @@
+name: Sync Core Provider Contract
+
+on:
+  workflow_dispatch:
+  push:
+    branches:
+      - main
+    paths:
+      - contracts/core-provider.openapi.yaml
+      - routes/**
+
+jobs:
+  sync-core-provider-contract:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    steps:
+      - name: Checkout source repository
+        uses: actions/checkout@v4
+
+      - name: Checkout rerum_openapi
+        uses: actions/checkout@v4
+        with:
+          repository: cubap/rerum_openapi
+          token: ${{ secrets.BRY_PAT }}
+          path: rerum_openapi
+
+      - name: Copy provider contract baseline
+        run: |
+          cp contracts/core-provider.openapi.yaml rerum_openapi/seams/tinynode-to-rerum/openapi/baseline.openapi.yaml
+
+      - name: Create sync pull request
+        uses: peter-evans/create-pull-request@v7
+        with:
+          token: ${{ secrets.BRY_PAT }}
+          path: rerum_openapi
+          branch: automation/sync-rerum-core-provider-contract
+          delete-branch: true
+          commit-message: Sync RERUM core provider contract from rerum_server_nodejs
+          title: Sync RERUM core provider contract from rerum_server_nodejs
+          body: |
+            Automated sync from `${{ github.repository }}` at `${{ github.sha }}`.
+
+            Source:
+            - `contracts/core-provider.openapi.yaml`
+
+            Target:
+            - `seams/tinynode-to-rerum/openapi/baseline.openapi.yaml`
diff --git a/__tests__/core_provider_contract.test.js b/__tests__/core_provider_contract.test.js
new file mode 100644
index 0000000..b358a89
--- /dev/null
+++ b/__tests__/core_provider_contract.test.js
@@ -0,0 +1,111 @@
+import fs from "fs"
+import path from "path"
+import { fileURLToPath } from "url"
+
+const here = path.dirname(fileURLToPath(import.meta.url))
+const repoRoot = path.resolve(here, "..")
+const apiRoutesPath = path.join(repoRoot, "routes", "api-routes.js")
+const contractPath = path.join(repoRoot, "contracts", "core-provider.openapi.yaml")
+
+const skippedMountedRouters = new Set([
+  "./static.js",
+  "./compatability.js"
+])
+
+function normalizeRoutePath(routePath) {
+  return routePath.replace(/\/:([A-Za-z0-9_]+)/g, "/{id}")
+}
+
+function joinMountedPath(prefix, routePath) {
+  const suffix = routePath === "/" ? "" : routePath
+  return normalizeRoutePath(`${prefix}${suffix}`.replace(/\/+/g, "/"))
+}
+
+function parseImports(source) {
+  const imports = new Map()
+  const importPattern = /^import\s+(\w+)\s+from\s+'(\.\/[^']+)';?$/gm
+  for (const match of source.matchAll(importPattern)) {
+    imports.set(match[1], match[2])
+  }
+  return imports
+}
+
+function parseMountedRouters(source, imports) {
+  const mounted = []
+  const usePattern = /router\.use\('([^']+)',\s*(\w+)\)/g
+  for (const match of source.matchAll(usePattern)) {
+    const importPath = imports.get(match[2])
+    if (!importPath || skippedMountedRouters.has(importPath)) {
+      continue
+    }
+    mounted.push({
+      prefix: match[1],
+      filePath: path.join(repoRoot, "routes", importPath.replace("./", ""))
+    })
+  }
+  return mounted
+}
+
+function parseRouteOperations(filePath, prefix) {
+  const source = fs.readFileSync(filePath, "utf8")
+  const operations = new Set()
+  const routeBlockPattern = /router\.route\('([^']+)'\)([\s\S]*?)(?=\nrouter\.route\(|\nexport default)/g
+  for (const match of source.matchAll(routeBlockPattern)) {
+    const routePath = joinMountedPath(prefix, match[1])
+    const methods = new Set()
+    for (const methodMatch of match[2].matchAll(/\.(get|post|put|patch|delete|head)\(/g)) {
+      methods.add(methodMatch[1].toUpperCase())
+    }
+    for (const method of methods) {
+      operations.add(`${method} ${routePath}`)
+    }
+  }
+  return operations
+}
+
+function parseDirectOperations(source) {
+  const operations = new Set()
+  const directPattern = /router\.(get|post|put|patch|delete|head)\('([^']+)'/g
+  for (const match of source.matchAll(directPattern)) {
+    if (match[2] === "/api") {
+      operations.add(`${match[1].toUpperCase()} ${match[2]}`)
+    }
+  }
+  return operations
+}
+
+function getMountedCoreProviderOperations() {
+  const source = fs.readFileSync(apiRoutesPath, "utf8")
+  const imports = parseImports(source)
+  const operations = new Set(parseDirectOperations(source))
+  for (const mountedRouter of parseMountedRouters(source, imports)) {
+    for (const operation of parseRouteOperations(mountedRouter.filePath, mountedRouter.prefix)) {
+      operations.add(operation)
+    }
+  }
+  return Array.from(operations).sort()
+}
+
+function getContractOperations() {
+  const lines = fs.readFileSync(contractPath, "utf8").split("\n")
+  const operations = []
+  let currentPath = ""
+  for (const line of lines) {
+    const pathMatch = line.match(/^  (\/[^:]+):\s*$/)
+    if (pathMatch) {
+      currentPath = pathMatch[1]
+      continue
+    }
+    const methodMatch = line.match(/^    (get|post|put|patch|delete|head):\s*$/)
+    if (methodMatch && currentPath) {
+      operations.push(`${methodMatch[1].toUpperCase()} ${currentPath}`)
+    }
+  }
+  return operations.sort()
+}
+
+describe("core provider contract", () => {
+  it("matches the mounted core provider route surface", () => {
+    expect(getContractOperations()).toEqual(getMountedCoreProviderOperations())
+  })
+})
diff --git a/contracts/core-provider.openapi.yaml b/contracts/core-provider.openapi.yaml
new file mode 100644
index 0000000..a8070bc
--- /dev/null
+++ b/contracts/core-provider.openapi.yaml
@@ -0,0 +1,382 @@
+openapi: 3.0.3
+info:
+  title: RERUM Core Provider Contract
+  version: 1.0.0
+  description: Provider-maintained baseline for the core RERUM API surface.
+servers:
+  - url: https://store.rerum.io/v1
+paths:
+  /api:
+    get:
+      summary: Describe the core API endpoints
+      operationId: describeCoreApi
+      responses:
+        '200':
+          description: Available endpoint summary
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GenericObject'
+  /id/{id}:
+    get:
+      summary: Read object by id
+      operationId: getObjectById
+      parameters:
+        - $ref: '#/components/parameters/ObjectId'
+      responses:
+        '200':
+          description: Object payload
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GenericObject'
+    head:
+      summary: Read object headers by id
+      operationId: headObjectById
+      parameters:
+        - $ref: '#/components/parameters/ObjectId'
+      responses:
+        '200':
+          description: Object headers
+  /since/{id}:
+    get:
+      summary: Read updates since id
+      operationId: getSince
+      parameters:
+        - $ref: '#/components/parameters/ObjectId'
+      responses:
+        '200':
+          description: Incremental updates
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GenericArray'
+    head:
+      summary: Read update headers since id
+      operationId: headSince
+      parameters:
+        - $ref: '#/components/parameters/ObjectId'
+      responses:
+        '200':
+          description: Incremental update headers
+  /history/{id}:
+    get:
+      summary: Read object history by id
+      operationId: getHistory
+      parameters:
+        - $ref: '#/components/parameters/ObjectId'
+      responses:
+        '200':
+          description: Version history
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GenericArray'
+    head:
+      summary: Read object history headers by id
+      operationId: headHistory
+      parameters:
+        - $ref: '#/components/parameters/ObjectId'
+      responses:
+        '200':
+          description: Version history headers
+  /api/query:
+    post:
+      summary: Query objects
+      operationId: queryObjects
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/GenericObject'
+      responses:
+        '200':
+          description: Query results
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GenericArray'
+    head:
+      summary: Query object headers
+      operationId: headQueryObjects
+      responses:
+        '200':
+          description: Query result headers
+  /api/search:
+    post:
+      summary: Search objects by keywords
+      operationId: searchObjects
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/GenericObject'
+          text/plain:
+            schema:
+              type: string
+      responses:
+        '200':
+          description: Search results
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GenericArray'
+  /api/search/phrase:
+    post:
+      summary: Search objects by phrase
+      operationId: searchObjectsByPhrase
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/GenericObject'
+          text/plain:
+            schema:
+              type: string
+      responses:
+        '200':
+          description: Phrase search results
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GenericArray'
+  /api/create:
+    post:
+      summary: Create object
+      operationId: createObject
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/GenericObject'
+      responses:
+        '200':
+          description: Created object
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GenericObject'
+  /api/bulkCreate:
+    post:
+      summary: Create multiple objects
+      operationId: bulkCreateObjects
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/GenericArray'
+      responses:
+        '200':
+          description: Created objects
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GenericArray'
+  /api/update:
+    put:
+      summary: Update object
+      operationId: updateObject
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/GenericObject'
+      responses:
+        '200':
+          description: Updated object
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GenericObject'
+  /api/bulkUpdate:
+    put:
+      summary: Update multiple objects
+      operationId: bulkUpdateObjects
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/GenericArray'
+      responses:
+        '200':
+          description: Updated objects
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GenericArray'
+  /api/overwrite:
+    put:
+      summary: Overwrite object
+      operationId: overwriteObject
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/GenericObject'
+      responses:
+        '200':
+          description: Overwritten object
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GenericObject'
+  /api/patch:
+    patch:
+      summary: Patch object
+      operationId: patchObject
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/GenericObject'
+      responses:
+        '200':
+          description: Patched object
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GenericObject'
+    post:
+      summary: Patch object via override-compatible POST
+      operationId: patchObjectViaPost
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/GenericObject'
+      responses:
+        '200':
+          description: Patched object
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GenericObject'
+  /api/set:
+    patch:
+      summary: Add properties to object
+      operationId: setObjectProperties
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/GenericObject'
+      responses:
+        '200':
+          description: Updated object
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GenericObject'
+    post:
+      summary: Add properties to object via override-compatible POST
+      operationId: setObjectPropertiesViaPost
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/GenericObject'
+      responses:
+        '200':
+          description: Updated object
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GenericObject'
+  /api/unset:
+    patch:
+      summary: Remove properties from object
+      operationId: unsetObjectProperties
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/GenericObject'
+      responses:
+        '200':
+          description: Updated object
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GenericObject'
+    post:
+      summary: Remove properties from object via override-compatible POST
+      operationId: unsetObjectPropertiesViaPost
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/GenericObject'
+      responses:
+        '200':
+          description: Updated object
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GenericObject'
+  /api/delete:
+    delete:
+      summary: Delete object
+      operationId: deleteObject
+      responses:
+        '200':
+          description: Deletion result
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GenericObject'
+  /api/delete/{id}:
+    delete:
+      summary: Delete object by id
+      operationId: deleteObjectById
+      parameters:
+        - $ref: '#/components/parameters/ObjectId'
+      responses:
+        '200':
+          description: Deletion result
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GenericObject'
+  /api/release/{id}:
+    patch:
+      summary: Release object by id
+      operationId: releaseObject
+      parameters:
+        - $ref: '#/components/parameters/ObjectId'
+      responses:
+        '200':
+          description: Release result
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/GenericObject'
+components:
+  parameters:
+    ObjectId:
+      in: path
+      name: id
+      required: true
+      schema:
+        type: string
+  schemas:
+    GenericObject:
+      type: object
+      additionalProperties: true
+    GenericArray:
+      type: array
+      items:
+        $ref: '#/components/schemas/GenericObject'
diff --git a/test/contract-fixtures/tinynode-to-rerum.yaml b/test/contract-fixtures/tinynode-to-rerum.yaml
new file mode 100644
index 0000000..be20c4c
--- /dev/null
+++ b/test/contract-fixtures/tinynode-to-rerum.yaml
@@ -0,0 +1,44 @@
+interactions:
+  - description: Read an existing object by id
+    path: /id/{id}
+    method: get
+    expectedStatus: "200"
+    response:
+      body:
+        "@id": https://store.rerum.io/v1/id/test123
+        "@type": "http://www.w3.org/ns/oa#Annotation"
+        __rerum:
+          APIversion: "1.1.0"
+          generatedBy: https://store.rerum.io/agent
+          history:
+            prime: https://store.rerum.io/v1/id/test123
+            next: []
+            previous: ""
+          isReleased: ""
+          releaseDate: ""
+          releases:
+            next: []
+            previous: ""
+            replaces: ""
+
+  - description: Query objects
+    path: /api/query
+    method: post
+    expectedStatus: "200"
+    response:
+      body:
+        - "@id": https://store.rerum.io/v1/id/test123
+          "@type": "http://www.w3.org/ns/oa#Annotation"
+          __rerum:
+            APIversion: "1.1.0"
+            generatedBy: https://store.rerum.io/agent
+            history:
+              prime: https://store.rerum.io/v1/id/test123
+              next: []
+              previous: ""
+            isReleased: ""
+            releaseDate: ""
+            releases:
+              next: []
+              previous: ""
+              replaces: ""